VI.2 The Human Connectome

Olaf Sporns

Patric Hagmann

The image on the left shows a dissection of a human brain, performed by Eugen Ludwig and Josef Klingler from post-mortem tissue. The dissection reveals major anatomical features of the brain, but it does not reveal the brain’s connections. Shown on the right is a complete map of the major anatomical connections linking distinct regions of the cerebral cortex. The map was generated by biomedical engineer and neuroscientist Patric Hagmann in 2008 from magnetic resonance imaging data acquired from a living person. In its entirety, the brain consists of 1011 neurons and 1015 synaptic links, and the total wiring of the brain is estimated to span thousands of miles. The map in the middle shows the human connectome generated by computational cognitive neuroscientist Olaf Sporns using network science tools. Network analysis revealed robust small-world attributes, the existence of multiple modules interlinked by hub regions, and a structural core comprised of a set of brain regions that are highly interconnected. As multiple data sets from multiple participants were analyzed, it became clear that individual connectomes display unique structural features that might explain differences in cognition and behavior.

Acknowledgements: This exhibit is supported by the National
Science Foundation under Grant No. IIS-0238261, CHE-0524661,
IIS-0534909 and IIS-0715303, the James S. McDonnell Foundation;
Thomson Reuters; the Cyberinfrastructure for Network Science Center,
University Information Technology Services, and the School of
Library and Information Science, all three at Indiana University.
Some of the data used to generate the science maps is from the Web
of Science by Thomson Reuters and Scopus by Elsevier. Any opinions,
findings, and conclusions or recommendations expressed in this
material are those of the author(s) and do not necessarily reflect
the views of the National Science Foundation.